Transcript for Beyond the Border: Lawmakers Met with Drama During Ariz. Trip

We turn now to another big issue in american life -- immigration. The president spoke out today, so did a group of senators, who went to the border in arizona, and got a surprise. Abc's white house correspondent jim avila tells us what happened. Reporter: They came to nogales, arizona, to check to border security. The four u.S. Senators leading the charge in immigration reform, got way more than they expected. There just a few steps away, a desperate young woman sprinting her way out of mexico, only to be caught by the border patrol within seconds. john McCain tweeted, just witnessed a woman successfully climb a an foot bollard feans a few yards away from us. There are 22,000 border agents, 651 miles of fence, and six drones patrolling the mexican frontier making a successful crossing more difficult than ever. Apprehensions are down 78% from their peak in 2000. President obama today on univision. It's never going to be 1 ten% perfect. But we can continue to improve it and provide a clear path way for those who are already here. Reporter: Counterspoiz to stereotype six of the nation's safest cities are on or near the border. People who are debating about whether or not you should start immigration, say we have to wait until the border is secure. What do you say to that? I would say then we' ready to start right now because the border is secure. Reporter: Back in arizona, senator mccain hopes to convince skeptics from his base, that border security is improving. We will be able to say that we have a degree of border security that would allow people to move forward to a path to citizenship. Reporter: The senators say they hope to have an agreement on an immigration reform bill by the second week in april. Jim avila, abc news, washington.

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